/*-
 * Copyright (c) 2003, 2004, 2005 Lev Walkin <vlm@lionet.info>.
 * All rights reserved.
 * Redistribution and modifications are permitted subject to BSD license.
 */
#ifndef _ASN_CODECS_H_
#define _ASN_CODECS_H_

#ifdef __cplusplus
extern "C"
{
#endif

    struct asn_TYPE_descriptor_s; /* Forward declaration */

    /*
 * This structure defines a set of parameters that may be passed
 * to every ASN.1 encoder or decoder function.
 * WARNING: if max_stack_size member is set, and you are calling the
 *   function pointers of the asn_TYPE_descriptor_t directly,
 *   this structure must be ALLOCATED ON THE STACK!
 *   If you can't always satisfy this requirement, use ber_decode(),
 *   xer_decode() and uper_decode() functions instead.
 */
    typedef struct asn_codec_ctx_s
    {
        /*
	 * Limit the decoder routines to use no (much) more stack than a given
	 * number of bytes. Most of decoders are stack-based, and this
	 * would protect against stack overflows if the number of nested
	 * encodings is high.
	 * The OCTET STRING, BIT STRING and ANY BER decoders are heap-based,
	 * and are safe from this kind of overflow.
	 * A value from getrlimit(RLIMIT_STACK) may be used to initialize
	 * this variable. Be careful in multithreaded environments, as the
	 * stack size is rather limited.
	 */
        size_t max_stack_size; /* 0 disables stack bounds checking */
    } asn_codec_ctx_t;

    /*
 * Type of the return value of the encoding functions (der_encode, xer_encode).
 */
    typedef struct asn_enc_rval_s
    {
        /*
	 * Number of bytes encoded.
	 * -1 indicates failure to encode the structure.
	 * In this case, the members below this one are meaningful.
	 */
        ssize_t encoded;

        /*
	 * Members meaningful when (encoded == -1), for post mortem analysis.
	 */

        /* Type which cannot be encoded */
        struct asn_TYPE_descriptor_s *failed_type;

        /* Pointer to the structure of that type */
        void *structure_ptr;
    } asn_enc_rval_t;
#define _ASN_ENCODE_FAILED                                      \
    do                                                          \
        {                                                       \
            asn_enc_rval_t tmp_error;                           \
            tmp_error.encoded = -1;                             \
            tmp_error.failed_type = td;                         \
            tmp_error.structure_ptr = sptr;                     \
            ASN_DEBUG("Failed to encode element %s", td->name); \
            return tmp_error;                                   \
        }                                                       \
    while (0)
#define _ASN_ENCODED_OK(rval)       \
    do                              \
        {                           \
            rval.structure_ptr = 0; \
            rval.failed_type = 0;   \
            return rval;            \
        }                           \
    while (0)

    /*
 * Type of the return value of the decoding functions (ber_decode, xer_decode)
 * 
 * Please note that the number of consumed bytes is ALWAYS meaningful,
 * even if code==RC_FAIL. This is to indicate the number of successfully
 * decoded bytes, hence providing a possibility to fail with more diagnostics
 * (i.e., print the offending remainder of the buffer).
 */
    enum asn_dec_rval_code_e
    {
        RC_OK,    /* Decoded successfully */
        RC_WMORE, /* More data expected, call again */
        RC_FAIL   /* Failure to decode data */
    };
    typedef struct asn_dec_rval_s
    {
        enum asn_dec_rval_code_e code; /* Result code */
        size_t consumed;               /* Number of bytes consumed */
    } asn_dec_rval_t;
#define _ASN_DECODE_FAILED                                      \
    do                                                          \
        {                                                       \
            asn_dec_rval_t tmp_error;                           \
            tmp_error.code = RC_FAIL;                           \
            tmp_error.consumed = 0;                             \
            ASN_DEBUG("Failed to decode element %s", td->name); \
            return tmp_error;                                   \
        }                                                       \
    while (0)
#define _ASN_DECODE_STARVED            \
    do                                 \
        {                              \
            asn_dec_rval_t tmp_error;  \
            tmp_error.code = RC_WMORE; \
            tmp_error.consumed = 0;    \
            return tmp_error;          \
        }                              \
    while (0)

#ifdef __cplusplus
}
#endif

#endif /* _ASN_CODECS_H_ */
